1. Field of the Invention
This invention relates to structures, and in particular to a tornado resistant dome house.
2. Background of the Invention
Windstorms, including tornadoes and hurricanes, cause large amount of damage each year, both in the form of property structure damage and injury to persons. Winds associated with tornadoes in particular can rise to 300 miles per hour. Thus, it would be desirable to provide a dome house capable of resisting these magnitudes of storm.
There is a limit to the power of a tornado: the maximum pressure differential cannot exceed about 13 pounds per square inch (“psi”), because absolute pressure cannot descend below 0 psi at ground level, versus about 14.7 psi maximum ambient pressures nearby.
In order to survive this type of pressure differential and associated winds, a very streamlined shape is required, with little or no protrusions, overhangs, etc. Every portion of the outside must be a rounded self-supportive shape such that no matter which way the winds impinges upon it, the force is transmitted to an adjoining, adjacent area of wall downwind. Too large a building presents too much vertical surface for this purpose.
The structure must be very strong, in an engineering sense. Walls could be fabricated of precast and reinforced masonry (for high impact resistance), and formed to a pre-determined, constantly changing curvature (for minimal wind resistance).
Sections of wall must be secured together, one to another, both horizontally and vertically, to act as if they were one solid block, for wind resistance and turbulence resistance. This securing together can by accomplished by high strength steel cable or by heavy all-thread steel rods inside conduits cast in the wall and/or roof sections. In any event each row of sections would be cinched tightly against coiled steel spring tension, to permit expansion and contraction, with temperature and weather, without damage. This would also assist in erection (which may be accomplished using a fork lift), and makes it possible to replace any sections damaged by flying objects, if necessary.
The vertical cables or rods must be secured to the concrete foundation via anchors to avoid wind lift-off of the walls and roof. The low silhouette of the upper portion of the dome minimizes the wind resistance to high-velocity horizontal wind, and reduces the total weight that must be supported in this area. Because the roof is at a low confronting angle to any flying debris it is unlikely that the roof will become impacted and damaged by wind-borne objects, which are less likely to be massive at this reduced height.
Accordingly, it would be desirable to provide a tornado resistant dome house whose shape is low-profile and optimal for resisting strong winds associated with windstorms such as tornadoes and hurricanes, and whose construction features a plurality of tiles mutually connected by elongate members such as cables or metal rods, which hold the tiles together and prevent them from blowing apart in the presence of strong winds.